colorutils.cpp.hpp

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#define FASTLED_INTERNAL
#define __PROG_TYPES_COMPAT__

 
#include "fl/stl/int.h"
#include "platforms/is_platform.h"
#include "fl/math/math.h"
#include "fl/math/fixed_point.h"  // for fl::s16x16 — used by applyGamma_video
#include "fl/stl/stdint.h"
 
#include "fl/system/fastled.h"
#include "fl/stl/assert.h"
#include "fl/gfx/colorutils.h"
#include "fl/stl/compiler_control.h"
#include "fl/math/xymap.h"
#include "fl/stl/noexcept.h"
 
namespace fl {
 
namespace {
 
struct Oklab {
    float lightness;
    float green_red;
    float blue_yellow;
};
 
float signedCubeRoot(float value) FL_NO_EXCEPT {
    const float magnitude = fl::powf(fl::abs(value), 1.0f / 3.0f);
    return value < 0.0f ? -magnitude : magnitude;
}
 
Oklab rgbToOklab(const CRGB &rgb) FL_NO_EXCEPT {
    const float red = static_cast<float>(rgb.r) / 255.0f;
    const float green = static_cast<float>(rgb.g) / 255.0f;
    const float blue = static_cast<float>(rgb.b) / 255.0f;
 
    const float l = 0.4122214708f * red + 0.5363325363f * green +
                    0.0514459929f * blue;
    const float m = 0.2119034982f * red + 0.6806995451f * green +
                    0.1073969566f * blue;
    const float s = 0.0883024619f * red + 0.2817188376f * green +
                    0.6299787005f * blue;
 
    const float lRoot = signedCubeRoot(l);
    const float mRoot = signedCubeRoot(m);
    const float sRoot = signedCubeRoot(s);
 
    return {
        0.2104542553f * lRoot + 0.7936177850f * mRoot -
            0.0040720468f * sRoot,
        1.9779984951f * lRoot - 2.4285922050f * mRoot +
            0.4505937099f * sRoot,
        0.0259040371f * lRoot + 0.7827717662f * mRoot -
            0.8086757660f * sRoot,
    };
}
 
fl::u8 channelFromFloat(float value) FL_NO_EXCEPT {
    const float scaled = fl::roundf(fl::clamp(value, 0.0f, 1.0f) * 255.0f);
    return static_cast<fl::u8>(scaled);
}
 
CRGB oklabToRgb(const Oklab &lab) FL_NO_EXCEPT {
    const float lRoot = lab.lightness + 0.3963377774f * lab.green_red +
                        0.2158037573f * lab.blue_yellow;
    const float mRoot = lab.lightness - 0.1055613458f * lab.green_red -
                        0.0638541728f * lab.blue_yellow;
    const float sRoot = lab.lightness - 0.0894841775f * lab.green_red -
                        1.2914855480f * lab.blue_yellow;
    const float l = lRoot * lRoot * lRoot;
    const float m = mRoot * mRoot * mRoot;
    const float s = sRoot * sRoot * sRoot;
 
    return CRGB(channelFromFloat(4.0767416621f * l - 3.3077115913f * m +
                                 0.2309699292f * s),
                channelFromFloat(-1.2684380046f * l + 2.6097574011f * m -
                                 0.3413193965f * s),
                channelFromFloat(-0.0041960863f * l - 0.7034186147f * m +
                                 1.7076147010f * s));
}
 
} // namespace
 
CRGB &nblend(CRGB &existing, const CRGB &overlay, fract8 amountOfOverlay) FL_NO_EXCEPT {
    if (amountOfOverlay == 0) {
        return existing;
    }
 
    if (amountOfOverlay == 255) {
        existing = overlay;
        return existing;
    }
 
#if 0
    // Old blend method which unfortunately had some rounding errors
    fract8 amountOfKeep = 255 - amountOfOverlay;
 
    existing.red   = scale8_LEAVING_R1_DIRTY( existing.red,   amountOfKeep)
                    + scale8_LEAVING_R1_DIRTY( overlay.red,    amountOfOverlay);
    existing.green = scale8_LEAVING_R1_DIRTY( existing.green, amountOfKeep)
                    + scale8_LEAVING_R1_DIRTY( overlay.green,  amountOfOverlay);
    existing.blue  = scale8_LEAVING_R1_DIRTY( existing.blue,  amountOfKeep)
                    + scale8_LEAVING_R1_DIRTY( overlay.blue,   amountOfOverlay);
 
    cleanup_R1();
#else
    // Corrected blend method, with no loss-of-precision rounding errors
    existing.red = blend8(existing.red, overlay.red, amountOfOverlay);
    existing.green = blend8(existing.green, overlay.green, amountOfOverlay);
    existing.blue = blend8(existing.blue, overlay.blue, amountOfOverlay);
#endif
 
    return existing;
}
 
void nblend(CRGB *existing, const CRGB *overlay, fl::u16 count,
            fract8 amountOfOverlay) FL_NO_EXCEPT {
    for (fl::u16 i = count; i; --i) {
        nblend(*existing, *overlay, amountOfOverlay);
        ++existing;
        ++overlay;
    }
}
 
CRGB blend(const CRGB &p1, const CRGB &p2, fract8 amountOfP2) FL_NO_EXCEPT {
    CRGB nu(p1);
    nblend(nu, p2, amountOfP2);
    return nu;
}
 
CRGB blend_oklab(const CRGB &p1, const CRGB &p2, fract8 amountOfP2) FL_NO_EXCEPT {
    if (amountOfP2 == 0) { return p1; }
    if (amountOfP2 == 255) { return p2; }
 
    const Oklab first = rgbToOklab(p1);
    const Oklab second = rgbToOklab(p2);
    const float amount = static_cast<float>(amountOfP2) / 255.0f;
    const Oklab mixed = {
        first.lightness + (second.lightness - first.lightness) * amount,
        first.green_red + (second.green_red - first.green_red) * amount,
        first.blue_yellow + (second.blue_yellow - first.blue_yellow) * amount,
    };
    return oklabToRgb(mixed);
}
 
CRGB *blend(const CRGB *src1, const CRGB *src2, CRGB *dest, fl::u16 count,
            fract8 amountOfsrc2) FL_NO_EXCEPT {
    for (fl::u16 i = 0; i < count; ++i) {
        dest[i] = blend(src1[i], src2[i], amountOfsrc2);
    }
    return dest;
}
 
CHSV &nblend(CHSV &existing, const CHSV &overlay, fract8 amountOfOverlay,
             TGradientDirectionCode directionCode) FL_NO_EXCEPT {
    if (amountOfOverlay == 0) {
        return existing;
    }
 
    if (amountOfOverlay == 255) {
        existing = overlay;
        return existing;
    }
 
    fract8 amountOfKeep = 255 - amountOfOverlay;
 
    fl::u8 huedelta8 = overlay.hue - existing.hue;
 
    if (directionCode == SHORTEST_HUES) {
        directionCode = FORWARD_HUES;
        if (huedelta8 > 127) {
            directionCode = BACKWARD_HUES;
        }
    }
 
    if (directionCode == LONGEST_HUES) {
        directionCode = FORWARD_HUES;
        if (huedelta8 < 128) {
            directionCode = BACKWARD_HUES;
        }
    }
 
    if (directionCode == FORWARD_HUES) {
        existing.hue = existing.hue + scale8(huedelta8, amountOfOverlay);
    } else /* directionCode == BACKWARD_HUES */
    {
        huedelta8 = -huedelta8;
        existing.hue = existing.hue - scale8(huedelta8, amountOfOverlay);
    }
 
    existing.sat = scale8_LEAVING_R1_DIRTY(existing.sat, amountOfKeep) +
                   scale8_LEAVING_R1_DIRTY(overlay.sat, amountOfOverlay);
    existing.val = scale8_LEAVING_R1_DIRTY(existing.val, amountOfKeep) +
                   scale8_LEAVING_R1_DIRTY(overlay.val, amountOfOverlay);
 
    cleanup_R1();
 
    return existing;
}
 
void nblend(CHSV *existing, const CHSV *overlay, fl::u16 count,
            fract8 amountOfOverlay, TGradientDirectionCode directionCode) FL_NO_EXCEPT {
    if (existing == overlay)
        return;
    for (fl::u16 i = count; i; --i) {
        nblend(*existing, *overlay, amountOfOverlay, directionCode);
        ++existing;
        ++overlay;
    }
}
 
CHSV blend(const CHSV &p1, const CHSV &p2, fract8 amountOfP2,
           TGradientDirectionCode directionCode) FL_NO_EXCEPT {
    CHSV nu(p1);
    nblend(nu, p2, amountOfP2, directionCode);
    return nu;
}
 
CHSV *blend(const CHSV *src1, const CHSV *src2, CHSV *dest, fl::u16 count,
            fract8 amountOfsrc2, TGradientDirectionCode directionCode) FL_NO_EXCEPT {
    for (fl::u16 i = 0; i < count; ++i) {
        dest[i] = blend(src1[i], src2[i], amountOfsrc2, directionCode);
    }
    return dest;
}
 
void nscale8_video(CRGB *leds, fl::u16 num_leds, fl::u8 scale) FL_NO_EXCEPT {
    for (fl::u16 i = 0; i < num_leds; ++i) {
        leds[i].nscale8_video(scale);
    }
}
 
void fade_video(CRGB *leds, fl::u16 num_leds, fl::u8 fadeBy) FL_NO_EXCEPT {
    nscale8_video(leds, num_leds, 255 - fadeBy);
}
 
void fadeLightBy(CRGB *leds, fl::u16 num_leds, fl::u8 fadeBy) FL_NO_EXCEPT {
    nscale8_video(leds, num_leds, 255 - fadeBy);
}
 
void fadeToBlackBy(CRGB *leds, fl::u16 num_leds, fl::u8 fadeBy) FL_NO_EXCEPT {
    nscale8(leds, num_leds, 255 - fadeBy);
}
 
void fade_raw(CRGB *leds, fl::u16 num_leds, fl::u8 fadeBy) FL_NO_EXCEPT {
    nscale8(leds, num_leds, 255 - fadeBy);
}
 
void nscale8(CRGB *leds, fl::u16 num_leds, fl::u8 scale) FL_NO_EXCEPT {
    for (fl::u16 i = 0; i < num_leds; ++i) {
        leds[i].nscale8(scale);
    }
}
 
void fadeUsingColor(CRGB *leds, fl::u16 numLeds, const CRGB &colormask) FL_NO_EXCEPT {
    fl::u8 fr, fg, fb;
    fr = colormask.r;
    fg = colormask.g;
    fb = colormask.b;
 
    for (fl::u16 i = 0; i < numLeds; ++i) {
        leds[i].r = scale8_LEAVING_R1_DIRTY(leds[i].r, fr);
        leds[i].g = scale8_LEAVING_R1_DIRTY(leds[i].g, fg);
        leds[i].b = scale8(leds[i].b, fb);
    }
    cleanup_R1();
}
 
// CRGB HeatColor( fl::u8 temperature)
//
// Approximates a 'black body radiation' spectrum for
// a given 'heat' level.  This is useful for animations of 'fire'.
// Heat is specified as an arbitrary scale from 0 (cool) to 255 (hot).
// This is NOT a chromatically correct 'black body radiation'
// spectrum, but it's surprisingly close, and it's fast and small.
//
// On AVR/Arduino, this typically takes around 70 bytes of program memory,
// versus 768 bytes for a full 256-entry RGB lookup table.
 
CRGB HeatColor(fl::u8 temperature) FL_NO_EXCEPT {
    CRGB heatcolor;
 
    // Scale 'heat' down from 0-255 to 0-191,
    // which can then be easily divided into three
    // equal 'thirds' of 64 units each.
    fl::u8 t192 = scale8_video(temperature, 191);
 
    // calculate a value that ramps up from
    // zero to 255 in each 'third' of the scale.
    fl::u8 heatramp = t192 & 0x3F; // 0..63
    heatramp <<= 2;                 // scale up to 0..252
 
    // now figure out which third of the spectrum we're in:
    if (t192 & 0x80) {
        // we're in the hottest third
        heatcolor.r = 255;      // full red
        heatcolor.g = 255;      // full green
        heatcolor.b = heatramp; // ramp up blue
 
    } else if (t192 & 0x40) {
        // we're in the middle third
        heatcolor.r = 255;      // full red
        heatcolor.g = heatramp; // ramp up green
        heatcolor.b = 0;        // no blue
 
    } else {
        // we're in the coolest third
        heatcolor.r = heatramp; // ramp up red
        heatcolor.g = 0;        // no green
        heatcolor.b = 0;        // no blue
    }
 
    return heatcolor;
}

inline fl::u8 lsrX4(fl::u8 dividend) FL_NO_EXCEPT __attribute__((always_inline));
inline fl::u8 lsrX4(fl::u8 dividend) FL_NO_EXCEPT {
#if defined(FL_IS_AVR)
    dividend /= 2;
    dividend /= 2;
    dividend /= 2;
    dividend /= 2;
#else
    dividend >>= 4;
#endif
    return dividend;
}
 
namespace {
 
template <fl::size Size> struct RuntimeRGBPaletteReader {
    fl::span<const CRGB, Size> entries;
 
    CRGB read(fl::u8 index) const FL_NO_EXCEPT { return entries[index]; }
};
 
template <fl::size Size> struct ProgmemRGBPaletteReader {
    fl::span<const fl::u32, Size> entries;
 
    CRGB read(fl::u8 index) const FL_NO_EXCEPT {
        return CRGB(FL_PGM_READ_DWORD_NEAR(entries.data() + index));
    }
};
 
inline fl::u16 promote_channel_to_hd(fl::u8 channel) FL_NO_EXCEPT {
    return static_cast<fl::u16>(channel) << 8;
}
 
inline fl::u16 lerp_channel_to_hd(fl::u8 a, fl::u8 b, fl::u16 frac,
                                  fl::u32 segment_size) FL_NO_EXCEPT {
    const fl::u32 a_raw = static_cast<fl::u32>(a) << 8;
    const fl::u32 b_raw = static_cast<fl::u32>(b) << 8;
    return static_cast<fl::u16>(
        (a_raw * (segment_size - frac) + b_raw * frac) / segment_size);
}
 
inline CRGB16 promote_rgb_to_hd(const CRGB &rgb) FL_NO_EXCEPT {
    return CRGB16(u8x8::from_raw(promote_channel_to_hd(rgb.red)),
                  u8x8::from_raw(promote_channel_to_hd(rgb.green)),
                  u8x8::from_raw(promote_channel_to_hd(rgb.blue)));
}
 
inline fl::u16 scale_hd_channel(fl::u16 channel, fl::u8x8 scale) FL_NO_EXCEPT {
    const fl::u32 scaled =
        (static_cast<fl::u32>(channel) * scale.raw()) >> 8;
    return scaled > 0xFFFFu ? fl::u16(0xFFFF) : static_cast<fl::u16>(scaled);
}
 
inline void scale_rgb_hd(CRGB16 &rgb, fl::u8x8 brightness) FL_NO_EXCEPT {
    if (brightness.raw() == 256) {
        return;
    }
    rgb.r = u8x8::from_raw(scale_hd_channel(rgb.r.raw(), brightness));
    rgb.g = u8x8::from_raw(scale_hd_channel(rgb.g.raw(), brightness));
    rgb.b = u8x8::from_raw(scale_hd_channel(rgb.b.raw(), brightness));
}
 
template <fl::u8 PaletteBits, typename Reader>
CRGB16 ColorFromPaletteHDImpl(const Reader &reader, fl::u16 index,
                              fl::u8x8 brightness,
                              TBlendType blendType) FL_NO_EXCEPT {
    const fl::u8 frac_bits = 16 - PaletteBits;
    const fl::u8 palette_last = (fl::u8(1) << PaletteBits) - 1;
    const fl::u32 segment_size = fl::u32(1) << frac_bits;
    const fl::u8 entry_index = static_cast<fl::u8>(index >> frac_bits);
    const fl::u16 frac =
        static_cast<fl::u16>(index & (segment_size - fl::u32(1)));
 
    const CRGB rgb1 = reader.read(entry_index);
    CRGB16 out;
    if (frac && blendType != NOBLEND) {
        CRGB rgb2;
        if (entry_index == palette_last) {
            rgb2 = blendType == LINEARBLEND_NOWRAP ? rgb1 : reader.read(0);
        } else {
            rgb2 = reader.read(entry_index + 1);
        }
        out = CRGB16(u8x8::from_raw(lerp_channel_to_hd(
                         rgb1.red, rgb2.red, frac, segment_size)),
                     u8x8::from_raw(lerp_channel_to_hd(
                         rgb1.green, rgb2.green, frac, segment_size)),
                     u8x8::from_raw(lerp_channel_to_hd(
                         rgb1.blue, rgb2.blue, frac, segment_size)));
    } else {
        out = promote_rgb_to_hd(rgb1);
    }
 
    scale_rgb_hd(out, brightness);
    return out;
}
 
} // namespace
 
CRGB ColorFromPaletteExtended(const CRGBPalette32 &pal, fl::u16 index,
                              fl::u8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    // Extract the five most significant bits of the index as a palette index.
    fl::u8 index_5bit = (index >> 11);
    // Calculate the 8-bit offset from the palette index.
    fl::u8 offset = (fl::u8)(index >> 3);
    // Get the palette entry from the 5-bit index
    const CRGB *entry = &(pal[0]) + index_5bit;
    fl::u8 red1 = entry->red;
    fl::u8 green1 = entry->green;
    fl::u8 blue1 = entry->blue;
 
    fl::u8 blend = offset && (blendType != NOBLEND);
    if (blend) {
        if (index_5bit == 31) {
            entry = &(pal[0]);
        } else {
            entry++;
        }
 
        // Calculate the scaling factor and scaled values for the lower palette
        // value.
        fl::u8 f1 = 255 - offset;
        red1 = scale8_LEAVING_R1_DIRTY(red1, f1);
        green1 = scale8_LEAVING_R1_DIRTY(green1, f1);
        blue1 = scale8_LEAVING_R1_DIRTY(blue1, f1);
 
        // Calculate the scaled values for the neighbouring palette value.
        fl::u8 red2 = entry->red;
        fl::u8 green2 = entry->green;
        fl::u8 blue2 = entry->blue;
        red2 = scale8_LEAVING_R1_DIRTY(red2, offset);
        green2 = scale8_LEAVING_R1_DIRTY(green2, offset);
        blue2 = scale8_LEAVING_R1_DIRTY(blue2, offset);
        cleanup_R1();
 
        // These sums can't overflow, so no qadd8 needed.
        red1 += red2;
        green1 += green2;
        blue1 += blue2;
    }
    if (brightness != 255) {
        // nscale8x3_video(red1, green1, blue1, brightness);
        nscale8x3(red1, green1, blue1, brightness);
    }
    return CRGB(red1, green1, blue1);
}
 
CRGB16 ColorFromPaletteHD(const CRGBPalette32 &pal, fl::u16 index,
                          fl::u8x8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    return ColorFromPaletteHDImpl<5>(
        RuntimeRGBPaletteReader<32>{fl::span<const CRGB, 32>(&pal.entries[0], 32)},
        index, brightness, blendType);
}
 
CRGB ColorFromPalette(const CRGBPalette16 &pal, fl::u8 index,
                      fl::u8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    if (blendType == LINEARBLEND_NOWRAP) {
        index = map8(index, 0, 239); // Blend range is affected by lo4 blend of
                                     // values, remap to avoid wrapping
    }
 
    //      hi4 = index >> 4;
    fl::u8 hi4 = lsrX4(index);
    fl::u8 lo4 = index & 0x0F;
 
    // const CRGB* entry = &(pal[0]) + hi4;
    // since hi4 is always 0..15, hi4 * sizeof(CRGB) can be a single-byte value,
    // instead of the two byte 'int' that avr-gcc defaults to.
    // So, we multiply hi4 X sizeof(CRGB), giving hi4XsizeofCRGB;
    fl::u8 hi4XsizeofCRGB = hi4 * sizeof(CRGB);
    // We then add that to a base array pointer.
    const CRGB *entry = (CRGB *)((fl::u8 *)(&(pal[0])) + hi4XsizeofCRGB);
 
    fl::u8 blend = lo4 && (blendType != NOBLEND);
 
    fl::u8 red1 = entry->red;
    fl::u8 green1 = entry->green;
    fl::u8 blue1 = entry->blue;
 
    if (blend) {
 
        if (hi4 == 15) {
            entry = &(pal[0]);
        } else {
            ++entry;
        }
 
        fl::u8 f2 = lo4 << 4;
        fl::u8 f1 = 255 - f2;
 
        //    rgb1.nscale8(f1);
        fl::u8 red2 = entry->red;
        red1 = scale8_LEAVING_R1_DIRTY(red1, f1);
        red2 = scale8_LEAVING_R1_DIRTY(red2, f2);
        red1 += red2;
 
        fl::u8 green2 = entry->green;
        green1 = scale8_LEAVING_R1_DIRTY(green1, f1);
        green2 = scale8_LEAVING_R1_DIRTY(green2, f2);
        green1 += green2;
 
        fl::u8 blue2 = entry->blue;
        blue1 = scale8_LEAVING_R1_DIRTY(blue1, f1);
        blue2 = scale8_LEAVING_R1_DIRTY(blue2, f2);
        blue1 += blue2;
 
        cleanup_R1();
    }
 
    if (brightness != 255) {
        if (brightness) {
            ++brightness; // adjust for rounding
            // Now, since brightness is nonzero, we don't need the full
            // scale8_video logic; we can just to scale8 and then add one
            // (unless scale8 fixed) to all nonzero inputs.
            if (red1) {
                red1 = scale8_LEAVING_R1_DIRTY(red1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++red1;
#endif
            }
            if (green1) {
                green1 = scale8_LEAVING_R1_DIRTY(green1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++green1;
#endif
            }
            if (blue1) {
                blue1 = scale8_LEAVING_R1_DIRTY(blue1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++blue1;
#endif
            }
            cleanup_R1();
        } else {
            red1 = 0;
            green1 = 0;
            blue1 = 0;
        }
    }
 
    return CRGB(red1, green1, blue1);
}
 
CRGB ColorFromPaletteExtended(const CRGBPalette16 &pal, fl::u16 index,
                              fl::u8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    // Extract the four most significant bits of the index as a palette index.
    fl::u8 index_4bit = index >> 12;
    // Calculate the 8-bit offset from the palette index.
    fl::u8 offset = (fl::u8)(index >> 4);
    // Get the palette entry from the 4-bit index
    const CRGB *entry = &(pal[0]) + index_4bit;
    fl::u8 red1 = entry->red;
    fl::u8 green1 = entry->green;
    fl::u8 blue1 = entry->blue;
 
    fl::u8 blend = offset && (blendType != NOBLEND);
    if (blend) {
        if (index_4bit == 15) {
            entry = &(pal[0]);
        } else {
            entry++;
        }
 
        // Calculate the scaling factor and scaled values for the lower palette
        // value.
        fl::u8 f1 = 255 - offset;
        red1 = scale8_LEAVING_R1_DIRTY(red1, f1);
        green1 = scale8_LEAVING_R1_DIRTY(green1, f1);
        blue1 = scale8_LEAVING_R1_DIRTY(blue1, f1);
 
        // Calculate the scaled values for the neighbouring palette value.
        fl::u8 red2 = entry->red;
        fl::u8 green2 = entry->green;
        fl::u8 blue2 = entry->blue;
        red2 = scale8_LEAVING_R1_DIRTY(red2, offset);
        green2 = scale8_LEAVING_R1_DIRTY(green2, offset);
        blue2 = scale8_LEAVING_R1_DIRTY(blue2, offset);
        cleanup_R1();
 
        // These sums can't overflow, so no qadd8 needed.
        red1 += red2;
        green1 += green2;
        blue1 += blue2;
    }
    if (brightness != 255) {
        // nscale8x3_video(red1, green1, blue1, brightness);
        nscale8x3(red1, green1, blue1, brightness);
    }
    return CRGB(red1, green1, blue1);
}
 
CRGB16 ColorFromPaletteHD(const CRGBPalette16 &pal, fl::u16 index,
                          fl::u8x8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    return ColorFromPaletteHDImpl<4>(
        RuntimeRGBPaletteReader<16>{fl::span<const CRGB, 16>(&pal.entries[0], 16)},
        index, brightness, blendType);
}
 
CRGB ColorFromPaletteExtended(const TProgmemRGBPalette16 &pal, fl::u16 index,
                              fl::u8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    // Extract the four most significant bits of the index as a palette index.
    fl::u8 index_4bit = index >> 12;
    // Calculate the 8-bit offset from the palette index.
    fl::u8 offset = (fl::u8)(index >> 4);
    // Get the palette entry from the 4-bit index
    CRGB entry(FL_PGM_READ_DWORD_NEAR(&(pal[0]) + index_4bit));
    fl::u8 red1 = entry.red;
    fl::u8 green1 = entry.green;
    fl::u8 blue1 = entry.blue;
 
    fl::u8 blend = offset && (blendType != NOBLEND);
    if (blend) {
        if (index_4bit == 15) {
            entry = FL_PGM_READ_DWORD_NEAR(&(pal[0]));
        } else {
            entry = FL_PGM_READ_DWORD_NEAR(&(pal[1]) + index_4bit);
        }
 
        // Calculate the scaling factor and scaled values for the lower palette
        // value.
        fl::u8 f1 = 255 - offset;
        red1 = scale8_LEAVING_R1_DIRTY(red1, f1);
        green1 = scale8_LEAVING_R1_DIRTY(green1, f1);
        blue1 = scale8_LEAVING_R1_DIRTY(blue1, f1);
 
        // Calculate the scaled values for the neighbouring palette value.
        fl::u8 red2 = entry.red;
        fl::u8 green2 = entry.green;
        fl::u8 blue2 = entry.blue;
        red2 = scale8_LEAVING_R1_DIRTY(red2, offset);
        green2 = scale8_LEAVING_R1_DIRTY(green2, offset);
        blue2 = scale8_LEAVING_R1_DIRTY(blue2, offset);
        cleanup_R1();
 
        // These sums can't overflow, so no qadd8 needed.
        red1 += red2;
        green1 += green2;
        blue1 += blue2;
    }
    if (brightness != 255) {
        // nscale8x3_video(red1, green1, blue1, brightness);
        nscale8x3(red1, green1, blue1, brightness);
    }
    return CRGB(red1, green1, blue1);
}
 
CRGB16 ColorFromPaletteHD(const TProgmemRGBPalette16 &pal, fl::u16 index,
                          fl::u8x8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    return ColorFromPaletteHDImpl<4>(
        ProgmemRGBPaletteReader<16>{fl::span<const fl::u32, 16>(&pal[0], 16)},
        index, brightness, blendType);
}
 
CRGB ColorFromPaletteExtended(const TProgmemRGBPalette32 &pal, fl::u16 index,
                              fl::u8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    // Extract the five most significant bits of the index as a palette index.
    fl::u8 index_5bit = (index >> 11);
    // Calculate the 8-bit offset from the palette index.
    fl::u8 offset = (fl::u8)(index >> 3);
    // Get the palette entry from the 5-bit index
    CRGB entry(FL_PGM_READ_DWORD_NEAR(&(pal[0]) + index_5bit));
    fl::u8 red1 = entry.red;
    fl::u8 green1 = entry.green;
    fl::u8 blue1 = entry.blue;
 
    fl::u8 blend = offset && (blendType != NOBLEND);
    if (blend) {
        if (index_5bit == 31) {
            entry = FL_PGM_READ_DWORD_NEAR(&(pal[0]));
        } else {
            entry = FL_PGM_READ_DWORD_NEAR(&(pal[1]) + index_5bit);
        }
 
        // Calculate the scaling factor and scaled values for the lower palette
        // value.
        fl::u8 f1 = 255 - offset;
        red1 = scale8_LEAVING_R1_DIRTY(red1, f1);
        green1 = scale8_LEAVING_R1_DIRTY(green1, f1);
        blue1 = scale8_LEAVING_R1_DIRTY(blue1, f1);
 
        // Calculate the scaled values for the neighbouring palette value.
        fl::u8 red2 = entry.red;
        fl::u8 green2 = entry.green;
        fl::u8 blue2 = entry.blue;
        red2 = scale8_LEAVING_R1_DIRTY(red2, offset);
        green2 = scale8_LEAVING_R1_DIRTY(green2, offset);
        blue2 = scale8_LEAVING_R1_DIRTY(blue2, offset);
        cleanup_R1();
 
        // These sums can't overflow, so no qadd8 needed.
        red1 += red2;
        green1 += green2;
        blue1 += blue2;
    }
    if (brightness != 255) {
        // nscale8x3_video(red1, green1, blue1, brightness);
        nscale8x3(red1, green1, blue1, brightness);
    }
    return CRGB(red1, green1, blue1);
}
 
CRGB16 ColorFromPaletteHD(const TProgmemRGBPalette32 &pal, fl::u16 index,
                          fl::u8x8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    return ColorFromPaletteHDImpl<5>(
        ProgmemRGBPaletteReader<32>{fl::span<const fl::u32, 32>(&pal[0], 32)},
        index, brightness, blendType);
}
 
CRGB ColorFromPalette(const TProgmemRGBPalette16 &pal, fl::u8 index,
                      fl::u8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    if (blendType == LINEARBLEND_NOWRAP) {
        index = map8(index, 0, 239); // Blend range is affected by lo4 blend of
                                     // values, remap to avoid wrapping
    }
 
    //      hi4 = index >> 4;
    fl::u8 hi4 = lsrX4(index);
    fl::u8 lo4 = index & 0x0F;
 
    CRGB entry(FL_PGM_READ_DWORD_NEAR(&(pal[0]) + hi4));
 
    fl::u8 red1 = entry.red;
    fl::u8 green1 = entry.green;
    fl::u8 blue1 = entry.blue;
 
    fl::u8 blend = lo4 && (blendType != NOBLEND);
 
    if (blend) {
 
        if (hi4 == 15) {
            entry = FL_PGM_READ_DWORD_NEAR(&(pal[0]));
        } else {
            entry = FL_PGM_READ_DWORD_NEAR(&(pal[1]) + hi4);
        }
 
        fl::u8 f2 = lo4 << 4;
        fl::u8 f1 = 255 - f2;
 
        fl::u8 red2 = entry.red;
        red1 = scale8_LEAVING_R1_DIRTY(red1, f1);
        red2 = scale8_LEAVING_R1_DIRTY(red2, f2);
        red1 += red2;
 
        fl::u8 green2 = entry.green;
        green1 = scale8_LEAVING_R1_DIRTY(green1, f1);
        green2 = scale8_LEAVING_R1_DIRTY(green2, f2);
        green1 += green2;
 
        fl::u8 blue2 = entry.blue;
        blue1 = scale8_LEAVING_R1_DIRTY(blue1, f1);
        blue2 = scale8_LEAVING_R1_DIRTY(blue2, f2);
        blue1 += blue2;
 
        cleanup_R1();
    }
 
    if (brightness != 255) {
        if (brightness) {
            ++brightness; // adjust for rounding
            // Now, since brightness is nonzero, we don't need the full
            // scale8_video logic; we can just to scale8 and then add one
            // (unless scale8 fixed) to all nonzero inputs.
            if (red1) {
                red1 = scale8_LEAVING_R1_DIRTY(red1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++red1;
#endif
            }
            if (green1) {
                green1 = scale8_LEAVING_R1_DIRTY(green1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++green1;
#endif
            }
            if (blue1) {
                blue1 = scale8_LEAVING_R1_DIRTY(blue1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++blue1;
#endif
            }
            cleanup_R1();
        } else {
            red1 = 0;
            green1 = 0;
            blue1 = 0;
        }
    }
 
    return CRGB(red1, green1, blue1);
}
 
CRGB ColorFromPalette(const CRGBPalette32 &pal, fl::u8 index,
                      fl::u8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    if (blendType == LINEARBLEND_NOWRAP) {
        index = map8(index, 0, 247); // Blend range is affected by lo3 blend of
                                     // values, remap to avoid wrapping
    }
 
    fl::u8 hi5 = index;
#if defined(FL_IS_AVR)
    hi5 /= 2;
    hi5 /= 2;
    hi5 /= 2;
#else
    hi5 >>= 3;
#endif
    fl::u8 lo3 = index & 0x07;
 
    // const CRGB* entry = &(pal[0]) + hi5;
    // since hi5 is always 0..31, hi4 * sizeof(CRGB) can be a single-byte value,
    // instead of the two byte 'int' that avr-gcc defaults to.
    // So, we multiply hi5 X sizeof(CRGB), giving hi5XsizeofCRGB;
    fl::u8 hi5XsizeofCRGB = hi5 * sizeof(CRGB);
    // We then add that to a base array pointer.
    const CRGB *entry = (CRGB *)((fl::u8 *)(&(pal[0])) + hi5XsizeofCRGB);
 
    fl::u8 red1 = entry->red;
    fl::u8 green1 = entry->green;
    fl::u8 blue1 = entry->blue;
 
    fl::u8 blend = lo3 && (blendType != NOBLEND);
 
    if (blend) {
 
        if (hi5 == 31) {
            entry = &(pal[0]);
        } else {
            ++entry;
        }
 
        fl::u8 f2 = lo3 << 5;
        fl::u8 f1 = 255 - f2;
 
        fl::u8 red2 = entry->red;
        red1 = scale8_LEAVING_R1_DIRTY(red1, f1);
        red2 = scale8_LEAVING_R1_DIRTY(red2, f2);
        red1 += red2;
 
        fl::u8 green2 = entry->green;
        green1 = scale8_LEAVING_R1_DIRTY(green1, f1);
        green2 = scale8_LEAVING_R1_DIRTY(green2, f2);
        green1 += green2;
 
        fl::u8 blue2 = entry->blue;
        blue1 = scale8_LEAVING_R1_DIRTY(blue1, f1);
        blue2 = scale8_LEAVING_R1_DIRTY(blue2, f2);
        blue1 += blue2;
 
        cleanup_R1();
    }
 
    if (brightness != 255) {
        if (brightness) {
            ++brightness; // adjust for rounding
            // Now, since brightness is nonzero, we don't need the full
            // scale8_video logic; we can just to scale8 and then add one
            // (unless scale8 fixed) to all nonzero inputs.
            if (red1) {
                red1 = scale8_LEAVING_R1_DIRTY(red1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++red1;
#endif
            }
            if (green1) {
                green1 = scale8_LEAVING_R1_DIRTY(green1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++green1;
#endif
            }
            if (blue1) {
                blue1 = scale8_LEAVING_R1_DIRTY(blue1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++blue1;
#endif
            }
            cleanup_R1();
        } else {
            red1 = 0;
            green1 = 0;
            blue1 = 0;
        }
    }
 
    return CRGB(red1, green1, blue1);
}
 
CRGB ColorFromPalette(const TProgmemRGBPalette32 &pal, fl::u8 index,
                      fl::u8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    if (blendType == LINEARBLEND_NOWRAP) {
        index = map8(index, 0, 247); // Blend range is affected by lo3 blend of
                                     // values, remap to avoid wrapping
    }
 
    fl::u8 hi5 = index;
#if defined(FL_IS_AVR)
    hi5 /= 2;
    hi5 /= 2;
    hi5 /= 2;
#else
    hi5 >>= 3;
#endif
    fl::u8 lo3 = index & 0x07;
 
    CRGB entry(FL_PGM_READ_DWORD_NEAR(&(pal[0]) + hi5));
 
    fl::u8 red1 = entry.red;
    fl::u8 green1 = entry.green;
    fl::u8 blue1 = entry.blue;
 
    fl::u8 blend = lo3 && (blendType != NOBLEND);
 
    if (blend) {
 
        if (hi5 == 31) {
            entry = FL_PGM_READ_DWORD_NEAR(&(pal[0]));
        } else {
            entry = FL_PGM_READ_DWORD_NEAR(&(pal[1]) + hi5);
        }
 
        fl::u8 f2 = lo3 << 5;
        fl::u8 f1 = 255 - f2;
 
        fl::u8 red2 = entry.red;
        red1 = scale8_LEAVING_R1_DIRTY(red1, f1);
        red2 = scale8_LEAVING_R1_DIRTY(red2, f2);
        red1 += red2;
 
        fl::u8 green2 = entry.green;
        green1 = scale8_LEAVING_R1_DIRTY(green1, f1);
        green2 = scale8_LEAVING_R1_DIRTY(green2, f2);
        green1 += green2;
 
        fl::u8 blue2 = entry.blue;
        blue1 = scale8_LEAVING_R1_DIRTY(blue1, f1);
        blue2 = scale8_LEAVING_R1_DIRTY(blue2, f2);
        blue1 += blue2;
 
        cleanup_R1();
    }
 
    if (brightness != 255) {
        if (brightness) {
            ++brightness; // adjust for rounding
            // Now, since brightness is nonzero, we don't need the full
            // scale8_video logic; we can just to scale8 and then add one
            // (unless scale8 fixed) to all nonzero inputs.
            if (red1) {
                red1 = scale8_LEAVING_R1_DIRTY(red1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++red1;
#endif
            }
            if (green1) {
                green1 = scale8_LEAVING_R1_DIRTY(green1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++green1;
#endif
            }
            if (blue1) {
                blue1 = scale8_LEAVING_R1_DIRTY(blue1, brightness);
#if !(FASTLED_SCALE8_FIXED == 1)
                ++blue1;
#endif
            }
            cleanup_R1();
        } else {
            red1 = 0;
            green1 = 0;
            blue1 = 0;
        }
    }
 
    return CRGB(red1, green1, blue1);
}
 
CRGB ColorFromPalette(const CRGBPalette256 &pal, fl::u8 index,
                      fl::u8 brightness, TBlendType) FL_NO_EXCEPT {
    const CRGB *entry = &(pal[0]) + index;
 
    fl::u8 red = entry->red;
    fl::u8 green = entry->green;
    fl::u8 blue = entry->blue;
 
    if (brightness != 255) {
        ++brightness; // adjust for rounding
        red = scale8_video_LEAVING_R1_DIRTY(red, brightness);
        green = scale8_video_LEAVING_R1_DIRTY(green, brightness);
        blue = scale8_video_LEAVING_R1_DIRTY(blue, brightness);
        cleanup_R1();
    }
 
    return CRGB(red, green, blue);
}
 
CRGB ColorFromPaletteExtended(const CRGBPalette256 &pal, fl::u16 index,
                              fl::u8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    // Extract the eight most significant bits of the index as a palette index.
    fl::u8 index_8bit = index >> 8;
    // Calculate the 8-bit offset from the palette index.
    fl::u8 offset = index & 0xff;
    // Get the palette entry from the 8-bit index
    const CRGB *entry = &(pal[0]) + index_8bit;
    fl::u8 red1 = entry->red;
    fl::u8 green1 = entry->green;
    fl::u8 blue1 = entry->blue;
 
    fl::u8 blend = offset && (blendType != NOBLEND);
    if (blend) {
        if (index_8bit == 255) {
            entry = &(pal[0]);
        } else {
            entry++;
        }
 
        // Calculate the scaling factor and scaled values for the lower palette
        // value.
        fl::u8 f1 = 255 - offset;
        red1 = scale8_LEAVING_R1_DIRTY(red1, f1);
        green1 = scale8_LEAVING_R1_DIRTY(green1, f1);
        blue1 = scale8_LEAVING_R1_DIRTY(blue1, f1);
 
        // Calculate the scaled values for the neighbouring palette value.
        fl::u8 red2 = entry->red;
        fl::u8 green2 = entry->green;
        fl::u8 blue2 = entry->blue;
        red2 = scale8_LEAVING_R1_DIRTY(red2, offset);
        green2 = scale8_LEAVING_R1_DIRTY(green2, offset);
        blue2 = scale8_LEAVING_R1_DIRTY(blue2, offset);
        cleanup_R1();
 
        // These sums can't overflow, so no qadd8 needed.
        red1 += red2;
        green1 += green2;
        blue1 += blue2;
    }
    if (brightness != 255) {
        // nscale8x3_video(red1, green1, blue1, brightness);
        nscale8x3(red1, green1, blue1, brightness);
    }
    return CRGB(red1, green1, blue1);
}
 
CRGB16 ColorFromPaletteHD(const CRGBPalette256 &pal, fl::u16 index,
                          fl::u8x8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    return ColorFromPaletteHDImpl<8>(
        RuntimeRGBPaletteReader<256>{fl::span<const CRGB, 256>(&pal.entries[0], 256)},
        index, brightness, blendType);
}
 
CHSV ColorFromPalette(const CHSVPalette16 &pal, fl::u8 index,
                      fl::u8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    if (blendType == LINEARBLEND_NOWRAP) {
        index = map8(index, 0, 239); // Blend range is affected by lo4 blend of
                                     // values, remap to avoid wrapping
    }
 
    //      hi4 = index >> 4;
    fl::u8 hi4 = lsrX4(index);
    fl::u8 lo4 = index & 0x0F;
 
    //  CRGB rgb1 = pal[ hi4];
    const CHSV *entry = &(pal[0]) + hi4;
 
    fl::u8 hue1 = entry->hue;
    fl::u8 sat1 = entry->sat;
    fl::u8 val1 = entry->val;
 
    fl::u8 blend = lo4 && (blendType != NOBLEND);
 
    if (blend) {
 
        if (hi4 == 15) {
            entry = &(pal[0]);
        } else {
            ++entry;
        }
 
        fl::u8 f2 = lo4 << 4;
        fl::u8 f1 = 255 - f2;
 
        fl::u8 hue2 = entry->hue;
        fl::u8 sat2 = entry->sat;
        fl::u8 val2 = entry->val;
 
        // Now some special casing for blending to or from
        // either black or white.  Black and white don't have
        // proper 'hue' of their own, so when ramping from
        // something else to/from black/white, we set the 'hue'
        // of the black/white color to be the same as the hue
        // of the other color, so that you get the expected
        // brightness or saturation ramp, with hue staying
        // constant:
 
        // If we are starting from white (sat=0)
        // or black (val=0), adopt the target hue.
        if (sat1 == 0 || val1 == 0) {
            hue1 = hue2;
        }
 
        // If we are ending at white (sat=0)
        // or black (val=0), adopt the starting hue.
        if (sat2 == 0 || val2 == 0) {
            hue2 = hue1;
        }
 
        sat1 = scale8_LEAVING_R1_DIRTY(sat1, f1);
        val1 = scale8_LEAVING_R1_DIRTY(val1, f1);
 
        sat2 = scale8_LEAVING_R1_DIRTY(sat2, f2);
        val2 = scale8_LEAVING_R1_DIRTY(val2, f2);
 
        //    cleanup_R1();
 
        // These sums can't overflow, so no qadd8 needed.
        sat1 += sat2;
        val1 += val2;
 
        fl::u8 deltaHue = (fl::u8)(hue2 - hue1);
        if (deltaHue & 0x80) {
            // go backwards
            hue1 -= scale8(256 - deltaHue, f2);
        } else {
            // go forwards
            hue1 += scale8(deltaHue, f2);
        }
 
        cleanup_R1();
    }
 
    if (brightness != 255) {
        val1 = scale8_video(val1, brightness);
    }
 
    return CHSV(hue1, sat1, val1);
}
 
CHSV ColorFromPalette(const CHSVPalette32 &pal, fl::u8 index,
                      fl::u8 brightness, TBlendType blendType) FL_NO_EXCEPT {
    if (blendType == LINEARBLEND_NOWRAP) {
        index = map8(index, 0, 247); // Blend range is affected by lo3 blend of
                                     // values, remap to avoid wrapping
    }
 
    fl::u8 hi5 = index;
#if defined(FL_IS_AVR)
    hi5 /= 2;
    hi5 /= 2;
    hi5 /= 2;
#else
    hi5 >>= 3;
#endif
    fl::u8 lo3 = index & 0x07;
 
    fl::u8 hi5XsizeofCHSV = hi5 * sizeof(CHSV);
    const CHSV *entry = (CHSV *)((fl::u8 *)(&(pal[0])) + hi5XsizeofCHSV);
 
    fl::u8 hue1 = entry->hue;
    fl::u8 sat1 = entry->sat;
    fl::u8 val1 = entry->val;
 
    fl::u8 blend = lo3 && (blendType != NOBLEND);
 
    if (blend) {
 
        if (hi5 == 31) {
            entry = &(pal[0]);
        } else {
            ++entry;
        }
 
        fl::u8 f2 = lo3 << 5;
        fl::u8 f1 = 255 - f2;
 
        fl::u8 hue2 = entry->hue;
        fl::u8 sat2 = entry->sat;
        fl::u8 val2 = entry->val;
 
        // Now some special casing for blending to or from
        // either black or white.  Black and white don't have
        // proper 'hue' of their own, so when ramping from
        // something else to/from black/white, we set the 'hue'
        // of the black/white color to be the same as the hue
        // of the other color, so that you get the expected
        // brightness or saturation ramp, with hue staying
        // constant:
 
        // If we are starting from white (sat=0)
        // or black (val=0), adopt the target hue.
        if (sat1 == 0 || val1 == 0) {
            hue1 = hue2;
        }
 
        // If we are ending at white (sat=0)
        // or black (val=0), adopt the starting hue.
        if (sat2 == 0 || val2 == 0) {
            hue2 = hue1;
        }
 
        sat1 = scale8_LEAVING_R1_DIRTY(sat1, f1);
        val1 = scale8_LEAVING_R1_DIRTY(val1, f1);
 
        sat2 = scale8_LEAVING_R1_DIRTY(sat2, f2);
        val2 = scale8_LEAVING_R1_DIRTY(val2, f2);
 
        //    cleanup_R1();
 
        // These sums can't overflow, so no qadd8 needed.
        sat1 += sat2;
        val1 += val2;
 
        fl::u8 deltaHue = (fl::u8)(hue2 - hue1);
        if (deltaHue & 0x80) {
            // go backwards
            hue1 -= scale8(256 - deltaHue, f2);
        } else {
            // go forwards
            hue1 += scale8(deltaHue, f2);
        }
 
        cleanup_R1();
    }
 
    if (brightness != 255) {
        val1 = scale8_video(val1, brightness);
    }
 
    return CHSV(hue1, sat1, val1);
}
 
CHSV ColorFromPalette(const CHSVPalette256 &pal, fl::u8 index,
                      fl::u8 brightness, TBlendType) FL_NO_EXCEPT {
    CHSV hsv = *(&(pal[0]) + index);
 
    if (brightness != 255) {
        hsv.value = scale8_video(hsv.value, brightness);
    }
 
    return hsv;
}
 
namespace detail {
 
template <typename TSrcPalette, typename TDestPalette>
void UpscalePaletteRepeat(const TSrcPalette &srcpal,
                          TDestPalette &destpal) FL_NO_EXCEPT {
    const fl::u16 src_size = sizeof(srcpal.entries) / sizeof(srcpal.entries[0]);
    const fl::u16 dest_size =
        sizeof(destpal.entries) / sizeof(destpal.entries[0]);
    const fl::u16 repeat = dest_size / src_size;
    for (fl::u16 i = 0; i < src_size; ++i) {
        const fl::u16 start = i * repeat;
        for (fl::u16 j = 0; j < repeat; ++j) {
            destpal[static_cast<fl::u8>(start + j)] = srcpal[static_cast<fl::u8>(i)];
        }
    }
}
 
template <typename TSrcPalette, typename TDestPalette>
void UpscalePaletteInterpolated(const TSrcPalette &srcpal,
                                TDestPalette &destpal) FL_NO_EXCEPT {
    const fl::u16 dest_size =
        sizeof(destpal.entries) / sizeof(destpal.entries[0]);
    for (fl::u16 i = 0; i < dest_size; ++i) {
        destpal[static_cast<fl::u8>(i)] =
            ColorFromPalette(srcpal, static_cast<fl::u8>(i));
    }
}
 
} // namespace detail
 
void UpscalePalette(const class CRGBPalette16 &srcpal16,
                    class CRGBPalette256 &destpal256) FL_NO_EXCEPT {
    detail::UpscalePaletteInterpolated(srcpal16, destpal256);
}
 
void UpscalePalette(const class CHSVPalette16 &srcpal16,
                    class CHSVPalette256 &destpal256) FL_NO_EXCEPT {
    detail::UpscalePaletteInterpolated(srcpal16, destpal256);
}
 
void UpscalePalette(const class CRGBPalette16 &srcpal16,
                    class CRGBPalette32 &destpal32) FL_NO_EXCEPT {
    detail::UpscalePaletteRepeat(srcpal16, destpal32);
}
 
void UpscalePalette(const class CHSVPalette16 &srcpal16,
                    class CHSVPalette32 &destpal32) FL_NO_EXCEPT {
    detail::UpscalePaletteRepeat(srcpal16, destpal32);
}
 
void UpscalePalette(const class CRGBPalette32 &srcpal32,
                    class CRGBPalette256 &destpal256) FL_NO_EXCEPT {
    detail::UpscalePaletteInterpolated(srcpal32, destpal256);
}
 
void UpscalePalette(const class CHSVPalette32 &srcpal32,
                    class CHSVPalette256 &destpal256) FL_NO_EXCEPT {
    detail::UpscalePaletteInterpolated(srcpal32, destpal256);
}
 
#if 0
// replaced by PartyColors_p
void SetupPartyColors(CRGBPalette16& pal)
{
    fill_gradient( pal, 0, CHSV( HUE_PURPLE,255,255), 7, CHSV(HUE_YELLOW - 18,255,255), FORWARD_HUES);
    fill_gradient( pal, 8, CHSV( HUE_ORANGE,255,255), 15, CHSV(HUE_BLUE + 18,255,255), BACKWARD_HUES);
}
#endif
 
void nblendPaletteTowardPalette(CRGBPalette16 &current, CRGBPalette16 &target,
                                fl::u8 maxChanges) FL_NO_EXCEPT {
    if (maxChanges == 0) {
        return;
    }
 
    fl::u8 *p1;
    fl::u8 *p2;
    fl::u8 changes = 0;
 
    p1 = (fl::u8 *)current.entries;
    p2 = (fl::u8 *)target.entries;
 
    const fl::u8 totalChannels = sizeof(CRGBPalette16);
    for (fl::u8 i = 0; i < totalChannels; ++i) {
        // if the values are equal, no changes are needed
        if (p1[i] == p2[i]) {
            continue;
        }
 
        // if the current value is less than the target, increase it by one
        if (p1[i] < p2[i]) {
            ++p1[i];
            ++changes;
        }
 
        // if the current value is greater than the target,
        // increase it by one (or two if it's still greater).
        if (p1[i] > p2[i]) {
            --p1[i];
            ++changes;
            if (p1[i] > p2[i]) {
                --p1[i];
            }
        }
 
        // if we've hit the maximum number of changes, exit
        if (changes >= maxChanges) {
            break;
        }
    }
}
 
fl::u8 applyGamma_video(fl::u8 brightness, float gamma) FL_NO_EXCEPT {
    // Fixed-point path (s16x16) avoids pulling `__ieee754_pow` (libm,
    // ~2.7 KB) into release builds — see #2886 / #2910. Matches the
    // gamma8 LUT generator's approach in src/fl/math/ease.cpp.hpp.
    if (brightness == 0) {
        return 0;
    }
    constexpr fl::s16x16 inv_255_fp(1.0f / 255.0f);
    const fl::s16x16 gamma_fp(gamma);
    const fl::s16x16 x = static_cast<i32>(brightness) * inv_255_fp;  // [0, 1]
    const fl::s16x16 r = fl::s16x16::pow(x, gamma_fp);                // (0, 1]
    // Scale to u8 [0, 255] with round-half-up:
    //   result = ((u32)raw * 255 + 0x8000) >> 16
    const fl::u32 scaled =
        (static_cast<fl::u32>(r.raw()) * 255u + 0x8000u) >> 16;
    fl::u8 result = static_cast<fl::u8>(scaled > 255u ? 255u : scaled);
    if (result == 0) {
        result = 1; // never gamma-adjust a positive number down to zero
    }
    return result;
}
 
CRGB applyGamma_video(const CRGB &orig, float gamma) FL_NO_EXCEPT {
    CRGB adj;
    adj.r = applyGamma_video(orig.r, gamma);
    adj.g = applyGamma_video(orig.g, gamma);
    adj.b = applyGamma_video(orig.b, gamma);
    return adj;
}
 
CRGB applyGamma_video(const CRGB &orig, float gammaR, float gammaG,
                      float gammaB) FL_NO_EXCEPT {
    CRGB adj;
    adj.r = applyGamma_video(orig.r, gammaR);
    adj.g = applyGamma_video(orig.g, gammaG);
    adj.b = applyGamma_video(orig.b, gammaB);
    return adj;
}
 
CRGB &napplyGamma_video(CRGB &rgb, float gamma) FL_NO_EXCEPT {
    rgb = applyGamma_video(rgb, gamma);
    return rgb;
}
 
CRGB &napplyGamma_video(CRGB &rgb, float gammaR, float gammaG, float gammaB) FL_NO_EXCEPT {
    rgb = applyGamma_video(rgb, gammaR, gammaG, gammaB);
    return rgb;
}
 
void napplyGamma_video(CRGB *rgbarray, fl::u16 count, float gamma) FL_NO_EXCEPT {
    for (fl::u16 i = 0; i < count; ++i) {
        rgbarray[i] = applyGamma_video(rgbarray[i], gamma);
    }
}
 
void napplyGamma_video(CRGB *rgbarray, fl::u16 count, float gammaR,
                       float gammaG, float gammaB) FL_NO_EXCEPT {
    for (fl::u16 i = 0; i < count; ++i) {
        rgbarray[i] = applyGamma_video(rgbarray[i], gammaR, gammaG, gammaB);
    }
}
 
} // namespace fl